Didymocarpus pingyuanensis (Gesneriaceae), a new species endemic to Danxia landscape from Guangdong Province, China, and two new combinations in Didymocarpus

Didymocarpus pingyuanensis, endemic to the Danxia landscape in Pingyuan County, Guangdong, China, is described and illustrated here. This species can be distinguished from other members of Didymocarpus sect. Heteroboea by its calyx deeply 5-lobed to about three quarters of its length. The phylogenetic position of the new species within Didymocarpus was examined using nuclear ribosomal internal transcribed spacer (ITS) sequences. Based on phylogenetics analysis and morphological evidence, we propose two new combinations, elevating the two varieties to species level, namely D. yinzhengii and D. gamosepalus.